It’s official. The Porsche 918 Spyder, a plug-in hybrid supercar that so far has only been shown in concept form, is available for order and has been priced at $845,000 (not including destination and taxes). Porsche is only planning to build 918 examples of its stunning supercar so interested buyers better be quick.

What they will receive when deliveries finally commence in November of 2013 is a plug-in hybrid supercar with a total 718 horsepower on tap and a stellar fuel economy of more than 78 mpg based on the European combined driving cycle. The earlier a customer orders their vehicle, the earlier it will be delivered, as production is initialized in the same sequence in which orders are received.

Production development is proceeding apace in the wake of the outstanding customer response to the concept car unveiled at the 2010 Geneva Motor Show, a response that quickly spurred the production green light. The first examples will start being built in September of 2013 at Porsche’s main plant in Stuttgart-Zuffenhausen, Germany.

As previously reported, the 918 Spyder’s design is derived from the Carrera GT as well as the Porsche 917 and RS Spyder race cars. Unlike the original concept car, however, the production version of the two-seater, based on a carbon fiber monocoque, features a manual roof system with removable roof panels that can be stowed in the front luggage compartment.

The 918 Spyder is driven by a unique type of plug-in hybrid system. It comprises a high-revving V-8 engine with a displacement exceeding 4.0-liters and output of more than 500 horsepower. The mid-engine power unit is based on the racing engine of the successful Porsche RS Spyder and is matched to a seven-speed Porsche-Doppelkupplungsgetriebe (PDK) dual clutch transmission.

This mighty powerplant is complemented by two electric motors--one each on the front and rear axle--with a joint mechanical output of at least 218 horsepower. This configuration offers a variable all-wheel drive system with independent control of the propulsion force on both axles.

Powering the electric motors is a liquid-cooled lithium-ion battery that can be charged from a conventional domestic power socket, delivering an electric-only driving range of around 16 miles on a single charge. Topping up the batteries will take between 3-6 hours depending on the outlet used, but a quick charging option is planned to reduce charging time yet further.

So what it’ll do? The Porsche 918 Spyder should be able to sprint from 0-62 mph in just 3.2 seconds and go on to reach a top speed of 199 mph. Porsche predicts that it will be able to lap the Nurburgring Nordschleife in less than seven minutes and 30 seconds, beating the previous Carrera GT but still off the pace of the Nissan GT-R and Corvette ZR1. Note that the top speed in electric-only mode is limited to 94 mph in order to preserve battery life.

But alas, the car’s release is still some years away and the attention span of some millionaires may not last that long. Porsche has that covered. In order to keep its customers’ interests piqued, the automaker is launching a special edition of its 911 Turbo S.

Dubbed the 911 Turbo S “Edition 918 Spyder”, the special edition car is also limited to just 918 units and will only be offered to customers of the plug-in hybrid supercar. It features specials badging, illuminated door sills and the same acid green trim as seen on the original 918 Spyder concept car. First deliveries of this model are set to roll in June of this year and both Coupe and Cabriolet versions will be offered.

And no, this isn’t a free gift for those already lucky enough to be able afford the 918 Spyder plug-in hybrid supercar. It will cost $161,650 for the Coupe and $173,050 for the Cabriolet.